1. Field of the Invention
This invention relates generally to improvements in media sound playback systems, and, more particularly, to a new and improved system and method for dynamically synchronizing a digital soundtrack with a moving picture in motion picture media which includes a reference analog soundtrack, whereby the digital soundtrack plays back in synchronization with the moving picture for efficient and effective media sound playback.
2. Description of the Related Art
Digital sound has become an important part of the movie business, because of the high quality of reproduction which it provides.
Initially, analog sound was the only sound available for a movie. Analog sound in the movie business has made limited progress over the years, to being essentially marginally acceptable with relatively low quality sound provided thereby. The technical capabilities of the media for carrying analog sound were very limited, and did not meet the needs of the filmgoing public as well as the exhibitors to keep people coming to the theaters. In analog systems, there are two tracks in the film which play back in the theaters as four channels using a matrix encoding technology similar to quadrophonic sound to reproduce more channels than there actually are in the film, and similar in approach to stereophonic sound.
With the advent of digital sound in recent years, the digital sound provides a much greater dynamic range, representing a quality improvement over analog sound, in that the quiet movements are truly quiet, the loud moments may become very loud, and there are more surround channels including sub-woofer channels to support sounds such as for example very low frequency explosions.
At first, digital sound was an add-on to existing analog sound systems. The digital sound system included digital processing equipment including a digital reader to be mounted on the projector, and a separate digital processing box which fed digital sound to the amplifiers and to the loudspeakers. The only interface between the digital and analog systems was an automatic switch from the digital sound to the lower quality analog sound if there was a loss of digital sound, to provide continuous sound.
Presently, digital sound systems and analog sound systems are integrated with the speaker systems in many theaters. However, problems may arise even if there is no loss of the digital soundtrack, for example where the digital soundtrack loses synchronization with the moving picture while the movie is being shown, which would prevent movie-goers from enjoying the movie. This condition may arise for any one of a number of reasons.
The analog and digital soundtracks may be placed on the same film at different locations relative to each other, and at different locations relative to the location of the moving picture, to compensate for the locations of the analog and digital sound pickups relative to the picture gate and the lamphouse for projecting the moving picture. The digital soundtrack may be recorded in the film with a delay to compensate for the location of the digital sound pickup ahead of the location of the picture gate and the lamphouse, and to compensate for the distance between the digital sound pickup and the picture gate and the lamphouse. The delay initially synchronizes the digital soundtrack with the moving picture.
However, errors may be introduced in the pickup of the digital soundtrack which would cause loss of synchronization with the moving picture. The projectionist may thread the film in the projector in such a way that the digital soundtrack may be out of synchronization, by making the loop in the film too big or too small, which would change the distance of film travel between the digital sound pickup and the picture gate and lamphouse. Further, the design of the specific projector utilized may vary the distance between the digital sound pickup and the picture gate and lamphouse. Also, projectionists may not thread the film through all of the digital sound pickups associated with a projector, in systems wherein each pickup is adapted to function with one of a plurality of digital soundtrack formats. Errors may also occur in processing multiple prints of a film, causing the digital soundtrack to lose synchronization with the moving picture.
In view of these considerations, an effective operational system should be implemented in a motion picture projecting system for the dynamic synchronization of the digital soundtrack with the moving picture.
Therefore, those concerned with the development and use of digital sound in motion pictures have recognized the need for improved systems and methods for synchronizing the high quality digital soundtrack with the moving picture in a motion picture film, such that moviegoers may fully enjoy the experience of viewing a film without the disruption thereof caused by a loss of synchronization. Accordingly, the present invention fulfills these needs by providing efficient and effective dynamic synchronization of the digital soundtrack with the moving picture for an enhanced moviegoing experience and increased patron enjoyment.
Briefly, and in general terms, the present invention provides a new and improved system and method for dynamically synchronizing a digital soundtrack with a moving picture in an efficient and effective manner, while enhancing the viewing experience for the moviegoer at a motion picture theater. The system provides dynamic synchronization of the digital soundtrack by using an analog soundtrack in the same media as a reference, for effective synchronization thereof.
By way of example, and not by way of limitation, the present invention provides a new and improved system and method for dynamically synchronizing the digital film soundtrack from a transient in the digital and analog soundtracks.
More particularly, the present invention includes motion picture media including a moving picture, a digital soundtrack, and an analog soundtrack, and means for presenting the motion picture media. The system in accordance with the present invention further includes means for dynamically synchronizing the digital soundtrack and the moving picture with the analog soundtrack as a reference therefor. This is accomplished automatically through a feedback loop which generates a control signal from correlated information in the digital and analog soundtracks and adjusts a variable delay in the digital soundtrack responsive thereto.
Therefore, one advantage of the present invention is that it includes a system for effectively synchronizing the digital soundtrack with the moving picture in motion picture media.
A further advantage is that the present invention provides dynamically synchronizes the digital soundtrack with the moving picture while the motion picture media is being presented by the projecting device.
Another advantage is that of the present invention provides automatic synchronization of the digital soundtrack and the moving picture upon loss of synchronization while the motion picture media is being presented by the projecting device.
These and other objects and advantages of the invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings of illustrative embodiments.